March Mammal Madness Vocabulary Practice Test

The half of the Earth north of the equator is the northern hemisphere. Spring begins in March there because of the vernal equinox, when the Sun is directly over the equator and day length starts to exceed night length. The tilt of Earth’s axis means northern latitudes receive more sunlight as spring progresses, bringing warmer weather and new growth. The other choices don’t fit: the Arctic Circle is a latitude line, not a half of the planet; the Equator is the dividing line between hemispheres but isn’t itself a half; the Southern Hemisphere is the other half, where seasons are opposite to those in the north.